From: Bitterblue Smith <rtl8821cerfe2@xxxxxxxxx> commit 2a86aa9a1892d60ef2e3f310f5b42b8b05546d65 upstream. The Realtek rate control algorithm goes back and forth a lot between the highest and the lowest rate it's allowed to use. This is due to a lot of frames being dropped because the retry limits set by IEEE80211_CONF_CHANGE_RETRY_LIMITS are too low. (Experimentally, they are 4 for long frames and 7 for short frames.) The vendor drivers hardcode the value 48 for both retry limits (for station mode), which makes dropped frames very rare and thus the rate control is more stable. Because most Realtek chips handle the rate control in the firmware, which can't be modified, ignore the limits set by IEEE80211_CONF_CHANGE_RETRY_LIMITS and use the value 48 (set during chip initialisation), same as the vendor drivers. Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Bitterblue Smith <rtl8821cerfe2@xxxxxxxxx> Reviewed-by: Ping-Ke Shih <pkshih@xxxxxxxxxxx> Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxx> Link: https://lore.kernel.org/r/477d745b-6bac-111d-403c-487fc19aa30d@xxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 9 --------- 1 file changed, 9 deletions(-) --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c @@ -5500,7 +5500,6 @@ static int rtl8xxxu_config(struct ieee80 { struct rtl8xxxu_priv *priv = hw->priv; struct device *dev = &priv->udev->dev; - u16 val16; int ret = 0, channel; bool ht40; @@ -5510,14 +5509,6 @@ static int rtl8xxxu_config(struct ieee80 __func__, hw->conf.chandef.chan->hw_value, changed, hw->conf.chandef.width); - if (changed & IEEE80211_CONF_CHANGE_RETRY_LIMITS) { - val16 = ((hw->conf.long_frame_max_tx_count << - RETRY_LIMIT_LONG_SHIFT) & RETRY_LIMIT_LONG_MASK) | - ((hw->conf.short_frame_max_tx_count << - RETRY_LIMIT_SHORT_SHIFT) & RETRY_LIMIT_SHORT_MASK); - rtl8xxxu_write16(priv, REG_RETRY_LIMIT, val16); - } - if (changed & IEEE80211_CONF_CHANGE_CHANNEL) { switch (hw->conf.chandef.width) { case NL80211_CHAN_WIDTH_20_NOHT:
